Acid catalyzed, liquid phase preparation of methyl vinyl ketone

ABSTRACT

A process for obtaining methyl vinyl ketone by reacting acetone with formaldehyde in the presence of a strong acid in the liquid phase.

United States Patent [1 1 Ember ACID CATALYZED, LIQUID PHASE PREPARATION OF METHYL VINYL KETONE [75] Inventor: George Fznber, Hackensack, NJ.

[73] Assignee: Hofimann-La Roche lnc., Nutley,

22 Filed: Aug. 51, 1973 [21 Appl. No.: 393,519

Related U.S. Application Data [63] Continuation-impart of Ser. No. 296,407, Oct. I0,

OTHER PUBLICATIONS Nielsen, The Aldol Condensation, Organic Reactions,

[ 5] Dec. 23, 1975 Vol. 16, pp. 9-10 and 28-30.

Wesslen et aL, Acta Chemica Scandinavica 22( 1968), pp. 2085-2l00.

Nielson, The Aldol Condensation, Organic Reactions, Vol. 16, pp. 9 to l l.

Primary Examiner.lames 0. Thomas, Jr. Assistant Examiner-James H. Reamer Attorney, Agent, or FirmSamuel L. Welt; Jon S. Saxe; Richard A. Gaither ABSTRACT A process for obtaining methyl vinyl ketone by reacting acetone with formaldehyde in the presence of a strong acid in the liquid phase.

5 Claims, N0 Drawings ACID CATALYZEI), LIQUID PHASE PREPARATION OF METHYL VINYL KETONE CROSS REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part of patent application Ser. No. 296,407, filed Oct. [0, I972 now abandoned, entitled Acid Catalyzed, Liquid Phase Preparation of Methyl Vinyl Ketone.

BACKGROUND OF THE INVENTION This invention relates to the liquid phase production of methyl vinyl ketone from formaldehyde and acetone.

(LB-UHSLIIUHIICLI ketones have heretofore been obtained by reacting a ketone with formaldehyde at elevated temperatures in the presence of a solid catalyst. Among the liquid phase and vapor phase processes which utilize solid catalysts for making ozfi-unsaturated ketones are the processes described in British Pat. No. 993.389, German Pat. No. 734,278 and US. Pat. Nos. 3.578.702. 2.451.351 and 2.245.567.

These processes have been found. however. to be generally uneconomical for producing methyl vinyl ketone. The activity of the solid catalysts utilized in these processes has tended to be very short lived. This has been due to the tendency of formaldehyde and methyl vinyl ketone to polymerize on the surface of the catalyst at the elevated temperatures utilized. As a consequence. such solid catalysts have required frequent replacement and/or regeneration. The need to frequently replace and/or regenerate the solid catalyst has typically involved great expense and inconvenience. making the processes which utilize solid catalyst quite impractical for producing methyl vinyl ke tone.

SUMMARY OF THE INVENTION In accordance with the process of this invention. methyl vinyl ketone is obtained by reacting formaldehyde with acetone in the presence of a strong acid in the liquid phase.

By this liquid phase process. the problems attending frequent and costly solid catalyst replacement are avoided.

DETAILED DESCRIPTION OF THE INVENTION By the process of this invention. methyl vinyl ketone is obtained by reacting acetone with formaldehyde in the presence of a strong acid in the liquid phase. By the use of the term "in the liquid phase is meant that. under the reaction condition utilized, the strong acid. the acetone. and the formaldehyde form a liquid phase. substantially free of a solid or gaseous phase.

The liquid phase process of this in ention can be carried out continuously or batchwise in either a homogeneous system containing only one liquid phase or a heterogeneous system containing two or more liquid phasesv In a homogeneous system. the acid. formaldehy de and acetone form a single. homogeneous liquid phase. In a heterogeneous sy stem. the phases are separate and are intimately mixed in a con entional manncr. such as by rapidly agitating the phases.

.-\s an cmmplc of a heterogeneous system. in accordance w ith thi imention. is a two phase liquid system wherein one pha e consists of aqueous formaldehyde. trong acid and acetone and the second phase consists of methyl vinyl ketone and an inert solvent, which is immiscible with water and which extracts the methyl vinyl ketone from the aqueous phase as it is formed by the process of this invention. In this system. any conventional, slightly polar, inert organic solvent which is substantially immiscible with water and which will strip the methyl vinyl ketone from the reaction mixture as it is formed can be utilized. Preferred inert organic solvents include the chlorinated hydrocarbons. particularly tetrachloroethane. trichloroethylene and chlorobenzene.

In carrying out the liquid phase process of this invention. any conventional strong acid having a dissociation constant (in water at 25C.) of greater than about It) can be utilized. Among the preferred strong acids which can be utilized are the inorganic acids such as sulfuric. hydrochloric. perchloric. hydrobromic. hydroiodic, and phosphoric acid. Also among the preferred strong acids are the strong organic acids such as formic acid, oxalic acid. trichloroacetic acid and the sulfonic acids. The preferred sulfonic acids include the aliphatic sulfonic acids. especially the lower alkyl sul fonic acids. such as methanesulfonic acid. ethanesul fonic acid. l-propanesulfonic acid. Z-propanesulfonic acid. and trifluoromethanesultonic acid, particularly methanesulfonic acid; the alicyclic sulfonic acids. such as camphorsulfonic acid; and the aromatic sulfonic acids such as the toluene-sulfonic acids. particularly p-toluenesulfonic acid. the napthalenesultonic acids. particularly naphtalene-l-sulionic acid and napthalene2-sulfonic acid. benzenesulfonic acid. the nitrophenylsulfonic acids, particularly p-nitrophenylsulfonic acid, and the chlorobenzenesultlinic acids. particularly 4-chlorobenzenesulfonic acid. Among the foregoing strong acids. especially preferred for use in the process of this invention are the relatively inexpensive. strong inorganic acids such as sulfuric acid and phosphoric acid and the relatively non-corrosive. strong organic acids such as p-toluenesulfonic acid.

In the process of this invention. the reaction mixture. which consists of the acetone. formaldehyde and strong acid. can also contain various inert diluents. Among the inert diluents which can be present in the reaction mixture are methanol and water. These diluents can be present in trace or larger amounts without affecting the reaction. the concentration of the inert diluents not being critical in the process of this invention. Usually. between about /2 and 2 parts by weight of water and about 0.2 to 0.3 parts by weight of methanol are present in the reaction mixture for each part of formaldehyde added thereto. However. the concentration of water and of methanol in the reaction mixture can be higher or lower in accordance with the process of this invention. and the exact concentration of the inert diluents is not part of this invention.

In carrying out this liquid phase process. the ratio of formaldehyde to acetone in the reaction mixture is not critical. and equal parts by weight of these reactants can be utilized to obtain methyl vinyl ketone. It is preferred however. that an excess of acetone be utilized so that virtually all ofthe formaldehyde will be consumed in the reaction. Accordingly. it is preferred that a ratio of at least about 5 parts by weight of acetone per part by weight of formaldehyde be utilized. It is especially preferred to utilize between about I2 and 20 parts by weight of acetone per part by weight of formaldehyde with about 16 parts by weight of acetone per part by weight of formaldehyde being particularly preferred.

In this process. the amount of strong acid utilized to catalyze the reaction is not critical. and the acid can comprise between about 0005 and 2.0 percent by weight oi'the reaction mixture. It is especially preferred that the acid be present in an amount between about 0.0l and 0.50 percent by weight of the reaction mix ture. A particularly preferred amount of strong inor ganic acid is between about 0.05 and 0.10 percent by weight and a particularly preferred amount of strong organic acid is between about 0.0] and 0.02 percent by weight.

In carrying out the process of this invention. temperattire and pressure are not critical. and any combination of temperature and pressure conditions whereby the reaction mixture is maintained in the liquid phase. substantially free of a solid or a gaseous phase. can be utilized. In this process, temperatures of about 100C. to about 300C. are preferred. with 150C. to 250C. being particularly preferred. In this process. any pressure at or above the vapor pressure of the reaction mixture at the temperature of the reaction mixture can 4 since the strong acids utili/ed. particularly the inorganic acids. are generally quite inexpensive. it is preferred to use fresh acid as the catalyst in this process and not to recycle the used acid.

The examples which follow illustrate the process of this invention.

EXAMPLE 1 A mixture of 42.3 g of aqueous formaldehyde solulll tion (about 36 wtf/r formaldehyde in water and methanol] and 257.8 g. ol acetone was prepared. Then. 3.15 g. of aqueous sulfuric acid solution (l8 wtfi H 50 was added. A portion of this reaction mixture was charged into a pressure bomb. The reaction mixture 15 was analyzed by gas chromatography to determine the exact composition of the charge to the bomb. The bomb. containing the charge. was immersed in an oil bath heated to 203C. After 8 minutes. the bomb was quenched. The effluent from the bomb was analyzed by gas chromatography. The results are summarized below in Table 1.

Table l Methyl vinyl (\tL'Nil Formaldehyde Water Methanol Acetone Kelonc Charge. 5 ll 7.82 L87 K519 l l'l'luenl: 0.0o l2.-1| 1.75 76.72 0.03

be utilized to kee the reaction mixture in the liLUlLl P l in EXAMPLE 2 phase. L nder the prel'erred conditions ol'the process of this invention. pressures of about 300 p.s.i.a. to about [000 p.s.i.a. are generally utilized. However. in this process. greater pressures can also be utilized. such as a pressure of up to approximately 7000 p.s.i.a.. as well as lower pressures oi down to approximately [00 p,s.i.a.

By the liquid phase process ofthis invention. yields oi Utilizing the procedure of Example 1. a mixture of 35 g. of the formaldehyde solution. 210 g. of acetone. 1.63 ml. of water. and 0.17 ml. of phosphoric acid 85 WtT/r H;,PO,) was prepared and part of this mixture was charged into a pressure bomb. The bomb was im mersed for 20 minutes in a 200C. oil bath. The results are summarized below in Table 2.

Table 2 Methyl \inyl (at!) Formaldehyde Water Methanol Acetone Ketone Charge; 5.3) 813 I77 841m Effluent: 0,09 H04 l.(w-l- 77,92 $.30

EXAMPLE 3 A reaction mixture containing the formaldehyde solution. acetone and sulfuric acid (0.09 wt.7() was 50 charged into a stirred. tank reactor. The charge was rapidly heated to lb5C.. kept at this temperature for 30 minutes and then cooled. The charge and the effluent were analyzed by gas chromatography. The results are summarized below in Table 3.

Table 3 Methyl \in \l (t/ll Formaldehyde Water Methanol Acetone Ketonc Charge: 55] 7.9l l.7l 84,78 Effluent: 1.32 1. .16 L40 78.30 5.74

mixture in a conventional manner. it can be isolated. for example. by fractional distillation of the reaction EXAMPLE 4 mixture which results when the process of this invention is carried out in a homogeneous system. i.e.. with (\5 A charge containing the formaldehyde solution. aceone liquid phase. tone and sulfuric acid was heated at 220C. for 10 The acid used to catalyze the process can. if desired. minutes in a pressure bomb. The results are summabe recovered and reused or else discarded. However. rized below in Table 4.

Table 4 Forum! Sulfuric Methyl \myl (MM) dehydc .iler Methanol Acetone Acid Kelunc Charge: Fl) 57.95 3.2. 34 33 new lal'l'lucnt. M4 to. l x 3.41 27.75 o is 5.52

EXAMPLE 300C. a reaction mixture containing from about 5 to parts by weight of acetone to l part by weight of Utilizing the procedure of Example 1. a charge con formaldehyde and from about 0.01 to 0.5); by weight taining the formaldehyde solution. acetone and 03 of the reaction mixture of a strong acid havmg a dissouni/1 H SO was reacted in a pressure bomb at 220C. ciation constant of 10 selected from the group con for 4 minutes. The results are summarized below in sisting of sulfuric acid, an aliphatic. alicyclic or aro- Table 5. matic sulfonic acid. said reaction being carried out Table 5 Methyl \in \l (t W Formaldehyde Water Methanol Acetone Ketonc (hargcl 5.911 7.)2 L53 X4 51' Hllueni; mm 13.25 1.4l 76.] U 1 under a combination of temperatures and pressures EXAMPLE6 sufficient to maintain the I'LtlLIlOll mixture in a liquid A mixture of the formaldehyde solution. acetone and phase. p-toluencsulfonic acid (pTSAJ was pumped through a 2. The process of claim I wherein said acid is a sultubetype reactor of 290 ml. volume. This plug flow fonic acid. reactor was operated continuously for more than 100 3. The process of claim wherein said acid is p-tolhours at 10 ml./min. feed rate. The temperature and uene-sulfonic acid. pressure in the reactor were kept constant at 225C. 4. The process of claim I wherein said process is and 800 psig. respectively. The feed solution and reaccarried out at 150C. to 250C. tor effluent were analyzed by gas chromatography. The S. The process of claim 1 wherein 12 to 20 parts by results are summarized below in Table 6. weight of acetone are present in said liquid phase per Table 6 Methyl Formal- Vinyl Kctotlchydc Water Methanol Acetone Acetone butanol pTSA Others Feed twt/i) 5.8 9.7 2.] 32.3 i l|.0l l-Il'llucnt (i/ii 0.3. llb LX-l 74.0 7.72 3.06 (LlH 2.45

I claim: I. A process for obtaining methyl vinyl ketone compart by weight of formaldehyde.

prising reacting at a temperature of from 100C. to

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3 928 457 DATE December 23, 1975.

INVENTOR(S) I GEORGE EMBER It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, lines 36-38, Table 6,

"Methyl" Vinyl Acetone Should be:

Methyl Vinyl Ketone Signed and Scaled this A ttest:

RUTH C. MASON Arresting Officer C. MARSHALL DANN Commissioner ufPatenrs and Trademarks 

1. A PROCESS FOR OBTANING METHYL VINYL KETONE COMPRISING REACTING AT A TEMPERATURE OF FROM 100*C. TO 300*C., A REACTION MIXTURE CONTAINING FROM ABOUT 5 TO 20 PARTS BY WEIGHT OF ACETONE TO 1 PART BY WEIGHT OF FORMALDEHYDE AND FROM ABOUT 0.01 TO 0.5% BY WEIGHT OF THE REACTION MIXTURE OF A STRONG ACID HAVING A DISSOCIATION CONSTANTOF 10*4 SELECTED FROM THE GROUP CONSISTING OF SULFURIC ACID, AN ALIPHATIC, ALICYCLIC OR AROMATIC SULFONIC ACID, SAID REACTION BEING CARRIED OUT UNDER A COMBINATION OF TEMPERATURES AND PRUSSURES SUFFICIENT TO MAINTAIN THE REACTION MIXTURE IN A LIQUID PHASE.
 2. The process of claim 1 wherein said acid is a sulfonic acid.
 3. The process of claim 1 wherein said acid is p-toluene-sulfonic acid.
 4. The process of claim 1 wherein said process is carried out at 150*C. to 250*C.
 5. The process of claim 1 wherein 12 to 20 parts by weight of acetone are present in said liquid phase per part by weight of formaldehyde. 